Sweet god...the amount of definitions that should be saved for the avril lavigne fans...

People use the term emo music as a narrow minded attempt at attempting to categorize emotional music as 'everything that sounds like fall out boy'. It ain't. Here are the genres/musicians that could be referred to as 'emo', 'emo orientated' or perhaps 'crap' if you don't like it.

1980s hardcore/soulful punk: People argue that this laid the base for most 'emo' and it does share very similar qualities to more commercial forms we have today. Catchy guitar lyrics, rough lyrics dealing with love, unhapiness, anandonment, hatred, disullision, longer running times ( unlike all other forms of hardcore punk at the time ) etc. I would cite Husker Du's Zen Arcade as the best example of this era, but Rites of spring are another brilliant band.

Early 90s/90s screamo: As an off-shoot of emo this is included. Bands in the early 90s took emo on to more fast, distorted, screamed and abstract horizons. You can easily recognise alot of this music by these qualities but running times varied alot ( indian summer's track 12 ran for 17 minutes, where as jerome's dream songs ran for much shorter ), lyrics may be intelligible at parts or not atall, there may be huge intros or guitar riffs lasting the majority of the songs thrashed and or melodic. Indian summer, jerome's dream, joshua fit for battle, swing kids are examples. Modern pop punk should not be confused with this genre under pain of death.

mid 90s/90s emo: More melodic and slower than previous forms, 1990s saw the rise of 'indie-styled' emo outfits. Best recognisable by whispered lyrics, drowning guitar riffs, complicated and emotional song meanings. Exceptions to this such as Jimmy Eat World and get up kids resemble the modern pop punk movement far more with more pop orientated fast guitar lyrics, but they are far slower than the previous forms and overall emo followed an indie style. Texas is the reason, Christie front drive, Sunny Day real estate are examples, with jimmy eat world, get up kids, lifetime following faster formats and lyrical styles.

2000s: Pop punk sets the precident in this era with catchy guitar lyrics, simple chorus structure, fast pace, easy to understand songs etc. There does seem to be a modern divide between bands choosing harder guitar riffs and even screamed lyrics ( silverstein, hawthorne heights, mcr, fall out boy ) and others following more traditional pop formats of gentle guitar riffs and softer singing( simple plan, Taking back sunday ). Mcr, fall out boy, silverstein, hawthorne heights, a thorn for every heart, the used, funeral for a friend are examples.

2000s screamo: Perhaps as a front against the pop punk movement, bands tend mirror earlier, more hardcore forms of 'emo' with screamo being the most popular. Many little known, quite popular or even established screamo bands exist today following the general format of screamo in the early 90s. Funeral diner, circle takes the square, iwrotehaikusabout cannabilisminyouryearbook ( I had to space that ), emo summer ( who classify themselves as extremo...) are the best examples.

Confused yet?? You should be if you like this stuff, the world just doesn't get people like me and you and nothing should make sense.

there is a whole specram, drive through, which is near pop punk but too sad to be pop punk, examples of this would be home grown or allistar.
theres slow emo, often one male singer and an acoustic guitar example, dashboard confessional, coheid and cambria. then there is angst emo, typically two male singers two/three guitars with bright lights in background of video, these tend to sing about failed relationships, example taking back sunday. then there is post hard core which still comes under the categorie of emo, this is too heavy to be emo, but too soft to be hard core, will usually have a male being able to sing aswell as scream, these sing about failed relationships and use metaphores for words like 'and' example funeral for a friend. then there is hard core, this has similarities to metal, fast music, rythm and bass with the singer been so passionate about what they are singing they are litterally screaming, examples been poisen the well, atreyu.
then there is metal core, closest to metal and the last in the spectram, very fast, typiccally male siner heavy guitar riffs and more of a growl than a scream

taking back sunday
and won't you tell all your friends, youv'e got your gun to my head

It's not screaming and all of that. Emo is short for emotional, and emo music is emotional music, you dolt. Emo music is NOT punk rock or metal, nor even close to that. My sister claims that Escape the Fate is emo. No, it's not emo, but it's punk rock. Everyone that thinks Bullet for my Valentine, Blood on the Dance Floor, etc is emo, please go do us all a favor and go learn what emo music really is.

Also, if you claim your emo when you aren't even emotional, you are scene. Go learn something rather than being a stereotype.

emo is short for emotive hardcore, which formed in the 80's and 90's. bands like sunny day real estate, mineral, cap'n jazz, texas is the reason, the jazz june, promise ring, etc. emo is NOT my chemical romance, taking back sunday, any radio music, and emo is not mainstream.

Emo began as a music style in the '90's, and has become associated with bands like My Chemical Romance, Fallout Boy etc. It became a style that mostly (NOT ALWAYS) focuses on the vintage-look (retro brand names etc). Being emo myself, you're all gonna think 'OMG IT'S AN EMO, SHE'S, LIKE, GONNA BE, LIKE, OMGWTFBBQ MY LIFE SUCKS EMO'S RULE THEY'RE SO HARDCORE OMG LMAO' or something like that. (I'm not taking the mick out of anyone, I swear. Sorry if I offended someone.) I'm not depressed all the time, I'm not always writing dark poems about life, and I'm not anorexically skinny (I laugh about that).

Why is emo associated with self-harm? Just because some people decided that any depressing self-destruction music MUST be emo?

Emos are usually, as far as I know, into the retro emo bands that began the emo craze, and the more modern bands like Panic! @ The Disco etc. The most common feature of emo is the hair with a side-parting. The bangs are NOT always covering one eye, NOT always dark, NOT always straight, NOT always shaggy for boys and NOT always short for girls.

The thing I've noticed that made me laugh about people's descriptions for emo boys was that they all wear trousers fitted for girls. WHAT A CROCK. I've never seen an emo boy dressed in trousers that are fit for girls. It would look a bit dumb, I mean, with the hips and all. So what if the trousers might be tight? It doesn't mean they're for girls! SERIOUSLY STRANGE. But if there is an emo boy who wears girls trousers, SORRY.

Another big thing for emo is the gloves/bracelettes and scraves. NOT everyone wears them but it's pretty common, from what I've seen.

I AM NOT AN EXPERT. This is my opinion and it's not always right! Emo is a fashion sense that may have stereotypes but not all emos follow them. Who can tell me they know EXACTLY what the emo fashion is? Anyone? I don't think even emos can really tell me.

Him: Everyone says I'm not emo because my hair isn't an emo hairstyle

Her: Stereotypes are fun, lets point and laugh

*Him and Her both point and laugh at the steroetypes dancing on the ceiling as emo music plays some place random in the background*